Ventricular repolarization duration and dispersion adaptation after atropine induced rapid heart rate increase in healthy adults

Bergfeldt, Lennart; Lundahl, Gunilla; Bergqvist, Gabriel; Vahedi, Farzad; Gransberg, Lennart

doi:10.1016/j.jelectrocard.2017.03.014

Cited by 10 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The methodology followed the basic principles applied in our previous studies [16][17][18]. The protocol stipulated 5 minutes of supine rest with closed eyes and no conversation to allow heart rate stabilization and heart rate adaptation of ventricular repolarization before the VCG recording period of �5 min (preferably 8-10 min).…”

Section: Vcg Recordings and On-line Analysismentioning

confidence: 99%

“…The analysis software was developed from the CoroNet platform (Ortivus AB, Danderyd, Sweden) but using the tangent method for defining the end of the T wave which we have applied in beat-to-beat analyses of ventricular repolarization dynamics [16][17][18].…”

Section: Automatic Vcg Post-analysismentioning

confidence: 99%

“…facilitated by a web-based QT calculator [26,31], the tangent method has been favored by others [32]. The tangent method is more suitable than the threshold method for studying ventricular repolarization changes on a beat-to-beat level during rapid heart rate increase according to our own experience [16][17][18]. We therefore decided on the tangent method for the entirely automatic VCG analysis of saQRST complexes so that the same automatic method could be used for analyses of beat-to-beat and steady-state signalaveraged cardiac cycles.…”

Section: Plos Onementioning

confidence: 99%

See 2 more Smart Citations

Automatic identification of a stable QRST complex for non-invasive evaluation of human cardiac electrophysiology

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background A vectorcardiography approach to electrocardiology contributes to the non-invasive assessment of electrical heterogeneity in the ventricles of the heart and to risk stratification for cardiac events including sudden cardiac death. The aim of this study was to develop an automatic method that identifies a representative QRST complex (QRSonset to Tend) from a Frank vectorcardiogram (VCG). This method should provide reliable measurements of morphological VCG parameters and signal when such measurements required manual scrutiny. Methods Frank VCG was recorded in a population-based sample of 1094 participants (550 women) 50-65 years old as part of the Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot. Standardized supine rest allowing heart rate stabilization and adaptation of ventricular repolarization preceded a recording period lasting �5 minutes. In the Frank VCG a recording segment during steady-state conditions and with good signal quality was selected based on QRST variability. In this segment a representative signal-averaged QRST complex from cardiac cycles during 10s was selected. Twenty-eight morphological parameters were calculated including both conventional conduction intervals and VCG-derived parameters. The reliability and reproducibility of these parameters were evaluated when using completely automatic and automatic but manually edited annotation points.

show abstract

Section: Vcg Recordings and On-line Analysismentioning

confidence: 99%

Section: Automatic Vcg Post-analysismentioning

confidence: 99%

Section: Plos Onementioning

confidence: 99%

See 1 more Smart Citation

Automatic identification of a stable QRST complex for non-invasive evaluation of human cardiac electrophysiology

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The presence of EADs strongly correlates with the onset of dangerous cardiac arrhythmias, including torsades de pointes (TdP), which is a specific type of abnormal heart rhythm that can lead to sudden cardiac death, see [2][3][4]. Please see for more (biological/physiological) details [5][6][7][8][9][10][11]. In this paper, we will use the bifurcation analysis similar to [12][13][14] to study the system introduced in [1].…”

Section: Introductionmentioning

confidence: 99%

Bifurcation Analysis of a Certain Hodgkin-Huxley Model Depending on Multiple Bifurcation Parameters

Erhardt

2018

Mathematics

View full text Add to dashboard Cite

Abstract:In this paper, we study the dynamics of a certain Hodgkin-Huxley model describing the action potential (AP) of a cardiac muscle cell for a better understanding of the occurrence of a special type of cardiac arrhythmia, the so-called early afterdepolarisations (EADs). EADs are pathological voltage oscillations during the repolarisation or plateau phase of cardiac APs. They are considered as potential precursors to cardiac arrhythmia and are often associated with deficiencies in potassium currents or enhancements in the calcium or sodium currents, e.g., induced by ion channel diseases, drugs or stress. Our study is focused on the enhancement in the calcium current to identify regions, where EADs related to enhanced calcium current appear. To this aim, we study the dynamics of the model using bifurcation theory and numerical bifurcation analysis. Furthermore, we investigate the interaction of the potassium and calcium current. It turns out that a suitable increasing of the potassium current adjusted the EADs related to an enhanced calcium current. Thus, one can use our result to balance the EADs in the sense that an enhancement in the potassium currents may compensate the effect of enhanced calcium currents.

show abstract

“…They are caused by ion channel diseases, oxidative stress or drugs and are often associated with deficiencies in potassium currents or enhancements in calcium currents [4]. Furthermore, the presence of EADs strongly correlates with the onset of dangerous cardiac arrhythmias, including torsades de pointes (TdP), which is a specific type of abnormal heart rhythm that can lead to sudden cardiac death, see [5][6][7][8][9][10]. Furthermore, EADs are so-called mixed-mode oscillations (MMOs) [11], i.e., complex oscillatory waveforms that naturally occur in physiologically relevant dynamical processes.…”

Section: Introductionmentioning

confidence: 99%

Early Afterdepolarisations Induced by an Enhancement in the Calcium Current

Erhardt

2019

Processes

View full text Add to dashboard Cite

Excitable biological cells, such as cardiac muscle cells, can exhibit complex patterns of oscillations such as spiking and bursting. Moreover, it is well known that an enhancement in calcium currents may yield certain kind of cardiac arrhythmia, so-called early afterdepolarisations (EADs). The presence of EADs strongly correlates with the onset of dangerous cardiac arrhythmia. In this paper we study mathematically and numerically the dynamics of a cardiac muscle cell with respect to the calcium current by investigating a simplistic system of differential equations. For the study of this phenomena, we use bifurcation theory, numerical bifurcation analysis, geometric singular perturbation theory and computational methods to investigate a nonlinear multiple time scales system. It will turn out that EADs related to an enhanced calcium current are canard–induced and that we have to combine these theories to derive a better understanding of the dynamics behind EADs. Moreover, a suitable time scale separation argument determines the important and sensitive system parameters which are related to the occurrence of EADs.

show abstract

Ventricular repolarization duration and dispersion adaptation after atropine induced rapid heart rate increase in healthy adults

Cited by 10 publications

References 21 publications

Automatic identification of a stable QRST complex for non-invasive evaluation of human cardiac electrophysiology

Automatic identification of a stable QRST complex for non-invasive evaluation of human cardiac electrophysiology

Bifurcation Analysis of a Certain Hodgkin-Huxley Model Depending on Multiple Bifurcation Parameters

Early Afterdepolarisations Induced by an Enhancement in the Calcium Current

Contact Info

Product

Resources

About